Machine for extruding plastics



Feb. 16, 1932. PARKHURST 1,844,972

MACHINE FOR EXTRUDING PLASTICS Filed Dec. 16, 1930 2 Sheets-Sheet l A five/1,101".- W AW Feb. 16, 1932. F. A. PARKHURST 1,844,972

MACHIN FOR EXTRUDING PLASTICS Filed Dec. 16, 1930 2 Sheets-Sheet 2 J J J! In vezzzozt- M AW Q Patent edlFeb. 16, 1932 UNITEDISTATE-S PATENT OFFICE IT REDEBIO A. PAT, O! A, IABYLAND, ASSIGNOR TO THE mERLOID OOBPOB-ATION, INDIAN ORCHARD, MASSACHUSETTS, A CORPORATION OF MASSA- OEUSE'ITB Application fled Deoeinber 10, mo. Serial in. 502,857.

This invention relates to apparatus for forming a web or sheet .from plastic material. The apparatus of the invention is directed particularly to a die through which a mass of pyroxylinin plastic condition may be extruded under-heavy pressure to form a thin web of pyroxylin. It has been found by practical experience with apparatus for this purpose that the sheet produced is subject to contains minute waves which may not be apparent to the eye and do not affect the value of the material for certain uses but which render it unfit for purposes which a sheet of perfect uniformity is required.

It is the object of the present. invention to provide an improvement in apparatus of this type adapted to minimize the difficulties experienced with former apparatus and to produce a web or sheet of greater uniformity.

Before explaining in detail the present invention, it is to be understood that the inven-- tion'is not, limited its application to the details of construction and arrangement of parts illustrated in the accompanying drawmgsjsince theinventionis.capable of other embodiments and of being practised or carried out in various ways. Also it is to be I understood that the phraseology 'or terminology employed herein is for the purposev of description and not of limitation, and itis not intended to limitthe invention beyond the terms of the several claims ,hereto appended as considered in view of the prior art and the requirements thereof.

The invention will be more clearly understood from the following description in conjunction withfthe accompanying drawings:

in which, v

Fig. 1 is a top plan view of a die embodying the invention;

Fig. ,[2 is an elevational view of the same partly in section Fig. 3 is a sectional view takenupon the line 3-3 of Fig. 1; and

Fig. 4 is 'a sectional view taken upon the 7 line 4-4 of Fig. a

p One embodimento'f the invention is shown in the accompanying drawings for the purpose of illustration and comprises a substanvariations in thickness and frequently moms non nx'rnunr ue rmsmcs tially cylindrical casing10 integral with or otherwise suitably secured to an extrusion press 11 adjacent the nozzle 12 thereof. The casing 10 is provided with a cylindrical bore 15 which is surroundedby a water jacketformed by interconnecting passages 16 between the bore 15 and the outer surface of the casing. Water at a suitabledesired temperature is admitted to and discharged from the passages 16 through pipeconnect'fons 17. A lon 'tudinal opening 20 is formed in the w ll of t e casing 10 and communicates with t j e cylindrical bore 15. d

An eccentric flange 21 is suitably secured upon each endof the casing 10 by bolts .22 passing through arcuate slots 18 in the flange 21. Each of the eccentric flanges 21 is provided with a cylindrical portion 24 extending. inwardly therefrom and havinga bearing against the surface of the cylindrical 7 rotation inthe .bearing surfaces 27 of the bushings 30,is spaced from the surface of the cylin- 26. The outer surface of the roll drical bore 15 to provide an orifice 23 therebetween extending fromthe nozzle 12 and terminating in the opening 20. An, annular packing 8, preferably of U-shaped cross-section may be disposed between the abutting surfaces of the roll 30 and the eccentric flanges 21 and extend into cooperating an nular grooves 9 therein.

The roll 30 may be rotated throughsuitable driving connections including a gear 35 secured' upon the journal 32. Water at any suitable desired temperature ma be admitted to and discharged from the lnterior of the roll 30 through suitable pipe connections 36 positioned in the axial bores 37 in the journals 31 and 32. Qakage is prevented by in adjusted position as suitable packing 38 surrounding the pipe connections 36 and held in place by a stufling box 39. Bails 40 and 41 are suitably secured at their ends to the eccentric flanges 21 and bushings 26 respectively as by screws 42. A closure member 45 extends into the opening toward the roll and is mounted upon the end of the bottom wall of the nozzle 12 as by bolts 46 passing through slots 47 in the member 45. If desired, an adjustable sto screw 48 may be secured in the bottom wall of the nozzle 12 so as to abut the end of the member and may be locked by a lock nut 49. A guide roll 50 is mounted for rotation in suitablebearings 51 upon the casing 10 adjacent the edge of the opening 20. 1

In operation, power is supplied to rotate the roll 30 in the direction of the arrow in Fig. 3 and plastic material, such as celluloid in plastic condition, is forced under pressure through the nozzle 12 of the extrusion press 11 into the orifice 23 to form a web W. Therotationnof the roll 30 assists in moving the web of plastic material through the orifice 23 and at the same time exerts an ironing.

action upon the web tending to smooth and polish its surface. The web W is discharged from theorifice 23 over the rounded surface 19 through the opening 20 and upon the ro-' tatable guide roll 50 whence it passes to suitable drying and curing apparatus (not shown). The web W is maintained in a suitable plastic condition during its passage through the orifice by circulation ofv water at a suitable temperature through the passages 16 in the casing 10 and within the in-' terior of the hollow roll 30.

The position of the roll 30 within the bore 15 may be adjusted so that the orifice 23 gradually decreases in depth from its end communicating with the nozzle 12 towards its end communicating with the opening 20 by releasing the bolts 22 and 28 and turning the eccentric flange 21 and eccentric bushings 26 bv means of the bails 40 and 41 respectively. The final thickness of the web produced is determined by the depth of the orifice 23 at its discharge end. When it is desired to change the thickness of the web by adjusting the position of the roll 30, the position of the member 45 is changed to bring its curved end, which corresponds to the curvature of the roll, adjacent the surface of the roll. The

rotation of the roll causes the plastic material to move into the orifice 23 rather than past the member 45.

I claim:

1. In an apparatus for forming a web from plastic material, a die comprising a hollow stationary casing having a curved. inner surface, a member mounted for movement adjacent said surface, and means for moving said member to cause its surface to move relative to the curved inner surface of said casadj ustably vdrical surface to face spaced from the inner surface of the casing to provide an orifice therebetween communicating with said opening.

3. In an apparatus for forming a web from plastic material, a die comprising a stationary, hollow casing having a cylindrical inner surface and an o ening, a roll mounted for rotation within't e caslngwith its surface spaced from the inner surface of the casing to provide an orifice therebetween communicating with said opening and means for adjusting the position of said roll with respect to sa1d surface.

4. In an apparatus for forming a web from plastic material, a die comprisin a stationary hollowcasing having a cylin rical inner surface and an opening a roll mounted for rotation within the caslng with its surface spaced from the inner surface of the casing to provide an orifice therebetween communicatm' with said opening, and a guide roll moun ted for rotation upon said casing adjacent said opening.

5. In an apparatus for forming a web from plastic material, a die comprising a stationary hollow-casting having a cylindrical inner surface and an opening, a roll mounted for rotation within the casing and eccentrically positioned with respect to said cylinrovide an orifice therebetween of gradu y decreasing depth as it approaches said opening.

6. In an ap aratus for forming a web from plastic matenal, a die comprism a hollow stationary casin having a cylin rical bore and a lon 'tudmal openin an eccentric bushing ad ustably suppo in each end of said bore, and a roll rotatably supported in said bushing with itssurface s aced from the surface of said bone to provi e an orifice therebetween communicating with said openary hollow casing having a cylindrical bore a flange adjustand a. longitudinal opemng, ably mounted upon the endsof said casing having an opening therein eccentrically positioned with respectcto said bore, a bushing adjustably mounted in said opening having a bearing surface eccentrically positioned with respect to said opening, and a roll rotatably supported in said bearing surface with its surface spaced from said 'bore to provide an orifice therebetween' communicating with said longitudinal opening.

9. In an apparatus for forming a web from plastic material, a die comprising a hollow stationary casing having a cylindrical inner surface and a longitudinal opening, a roll mounted for rotation within the casing with its surface spaced from the inner surface of the casing to provide an orifice therebetween communicating at its ends with said opening, means for adjusting the position of said roll with respect to the inner surface of said casing, and means providing a passage connecting one end of said orifice including an adjustable member extending into said opening toward said roll.

10. In an apparatus for forming a web from plastic material, a die comprising a hollow stationary casing having a cylindrical bore and a longitudinal opening, a flange adjustably carried upon each end of said casing and provided with a cylindrical portion engaging said bore and having a cylindrical opening eccentrically positioned therein, a

bushing adjustably carried by said flange provided with a cylindrical portion engaging said opening and having a bearing surface eccentrically positioned therein, and a roll rotatably supported in said bearing surface with its surface spaced from said bore to provide an orifice therebetween communicating with said longitudinal opening.

In testimony whereof I aflix my signature.

FREDERIC A. PARKHURST. 

